1. Field of the Invention
The invention comprises a beneficial agent delivery device, and, more particularly, a method and apparatus for delivering a beneficial agent into a surrounding area.
2. Background Art
Devices for delivery of beneficial agents to a surrounding area are well known in the art. While devices are known, there is a constant need for an improved delivery apparatus which serves to more accurately, more easily and more effectively deliver a beneficial agent to a surrounding area.
One particular type of delivery device for the delivery of beneficial agents has taken advantage of the galvanic effect between two different materials. For example, a prior art device is shown in FIGS. 14 and 15 of the drawings generally as 200. In such a prior art device, cathode 201 is paired with anode rod 202 having a stack of ring-like elements 204 associated with the rod. As shown in FIG. 15, the ring-like members include internal reservoirs 306 of capable of holding a beneficial agent 208. The rings include seals 110 such that when the rings are stacked upon each other about the anode rod, the rings and seals serve to seal each of the internal reservoirs and portions of the anode from their surroundings. Due to the anode and cathode materials utilized, the anode corrodes when the materials are exposed to ambient conditions, or other predetermined conditions (i.e. a liquid or gas environment wherein the liquid or gas forms the electrolyte). As the anode corrodes beyond a ring member (as shown in FIG. 15), the ring member is no longer retained by the rod, and the ring member releases from the stack of rings, thereby exposing the subsequent ring, and, the reservoir holding the beneficial agent. At such time, the beneficial agent is released. This process continues until the anode is no longer exposed to the ambient conditions, or until the anode completely corrodes and releases all of the rings.
While such an apparatus has facilitated the delivery of beneficial agents, the apparatus includes several drawbacks. For example, the apparatus utilizes a single anode. Due to the single anode, it is very difficult to vary or control the rate at which the beneficial agent is exposed, or the rate at which the beneficial agent is released.
Thus it is an object of the invention to provide an improved apparatus and method of delivering a beneficial agent.